There is no safe level of exposure to second-hand tobacco smoke, the smoke which smokers exhale after inhaling from a lit cigarette. In adults, breathing second-hand tobacco smoke can heighten the risk of cardiovascular disease and lung cancer and worsen the effects of other illnesses such as bronchitis and asthma.

Evidence shows that exposing ex-smokers to other people’s tobacco smoke increases the chance of them relapsing to smoking.

Inhaling second-hand tobacco smoke is even more dangerous for children, as their airways are smaller and their immune systems less developed, which makes them more susceptible to the negative health effects of second-hand tobacco smoke.

There is emerging evidence that under some circumstances, tobacco smoke affects the air quality of outdoor locations just as much as indoor locations.

These new requirements are enforceable by law. The ban on smoking within four metres of a pedestrian entrance to or exit from a public building will be delayed for licensed premises and restaurants until 6 July 2015.